Lubricant



Patented 1937 UNITED STATES LUBRICANT Harry T. Bennett and Clare Prather, Tulsa, Okla., assignors to Mid-Continent Petroleum Corpora-v tion, Tulsa, Okla, a corporation of Delaware No Drawing. Application February 4, 19 5,

Serial No. 4,874

This invention relates to lubricantsyand more specifically to lubricants adapted to withstand high pressures.

In the construction of modern automobiles having low centers of gravity, it has been found necessary to greatly reduce the size of the differential gears atthe rear axle, so as to obtain a satisfactory ground clearance. At the same time, due to the demand for increased acceleration, speed, and hill-climbing ability, the horse power of the engines have been very greatly increased.

The reduction of the size of the gears, and the increase in horse power has greatly increased the pressure at the gears. This pressure has been increased to such an extent that the oil film between the meshing teeth of the gears is ruptured when the straight mineral lubricating oils are employed. The extremely high pressure and lack of adequate lubrication results in rapid wearing and severe stresses due to the intense friction at the contacting faces of the gear teeth.

One of the objects of this invention, therefore, is to produce a lubricant, which has excellent lubricating properties when subjected to high pressures between the surfaces to be lubricated.

A lubricant adapted to withstand high pres sure may be produced by blending a sulphurized saponifiable oil, such as animal, or vegetable, oil, with a mineral oil. Such a lubricant, however, has not proven satisfactory as a relatively large quantity of the saponifiable oil has been required to produce the desired result. Most animal oils have a high pour test which raises the pour test of the ultimate blend. Moreover, sulphurized animal and vegetable oils polymerize and oxidize to form viscous and rubber-like materials harmfulto lubrication. These effects are in proportion to the amount of animal and vegetable oils employed in the blend.

We have found that the addition of diphenyl to a mineral oil will produce a lubricant hav ing the property of withstanding high pressures. This blend, while satisfactory for many uses, can be improved by the addition of a small quantity of saponifiable 011.

More specifically stated, a lubricant having excellent lubricating properties at extremely high pressures can be produced by blending a mineral lubricating oil with diphenyl and a vegetable or animal oil.

Nine per cent of a saponifiable oil, for example sulphurized fatty oil, in mineral lubricating oil will meet extreme pressure specifications. However, this large percentage of the saponifiable oil will greatly increase the pour test.

Five per cent of diphenyl in mineral oil, without the addition of any saponifiable oil, resulted in a blend that withstood high pressure, and the diphenyl did not affect the pour point of the oil.

However, we obtained better results from a blend containing a smaller percentage of diphenyl and a small quantity of saponifiable oil. This blend withstood higher pressures, and the small quantities of saponifiable oil and diphenyl did not raise the pour point.

The results of some of the tests using the mineral oil alone, and also with different percentages of saponifiable oil and diphenyl, appear as fol- The bright stock referred to above is a pctroleum lubricating oil having a viscosity of 100 at 210" F.

To provide for extreme pressures, it may be desirable to blend in the mineral oil as much as'25 per cent of the sulphurized base, depending upon the kind of sulphurized base employed. The proportions of diphenyl can likewise be varied within wide limits to meet different requirements.

In the preferred form of the invention, we employ:

Per cent Diphenyl 0.1 to 5 sulphurized animal 1 or sulphurized vegetable oil (saponifiable oil)--- 1.0 to 15 Mineral oil 80 to 98.9

In another form of our invention we employ ortho-hydroxy diphenyl as described and claimed in a division of this application filed by us on September 13, 1935, Serial No. 40,396. A specific example of a lubricant including the orthohydr'oxy diphenyl appears as follows:

' Per cent o-Hydroxy diphenyl 1.5 sulphurized animal oil or sulphurized base vegetable oil (saponifiable oil) Mineral nil gave satisfactory results.

The primary object is to produce an extreme pressure lubricant for gears but the composition could be used in many types of lubrication, such as crankcase oils, spindle oils, etc., and could also be incorporated into the semi-fluid lubricants commonly known as greases. For the crankable oil.

Instead 01 containing sulphur, the saponlflable oil may contain combined chlorine or phosphorus,

or combinations of sulphur, chlorine or phosphorus compounds, each oi. which is a non-metallic element.

The advantage of the diphenyl or hydroxy diphenyl is that it either makes the use oi! the animal or vegetable oil unnecessary, or reduces the quantity required.

We claim:

1. A lubricant adapted to withstand high pressures comprising a mineral lubricating oil containing 0.1 to per cent of diphenyl.

2. A lubricant adapted to withstand high pressures comprising a mineral lubricating oil containing 0.1 to 5 percent diphenyl and a. saponiflable oil.

3. A lubricant adapted to withstand high pressures comprising a mineral lubricating oil containing 0.1 to 5 percent diphenyl and a saponiflable oil in the group of animal and vegetable oils.

4. A lubricant comprising a mineral lubricating oil, 0.1 to 5 percent diphenyl and a saponinable oil containing an element in the chlorine and phosphorus.

group of sulphur,

5. A lubricant comprising more than 80 per cent mineral lubricating oil, 0.1 to 5 per cent of oil containing an element in the group of sulphur,

chlorine and phosphorus.

7. A lubricant comprising more than 80 per cent mineral lubricating oil, 0.1 to 5 per cent or diphenyl, and l to 15 per cent of saponi'fiable oil in the group of animal and vegetable'oils containing an element in the group of sulphur, chlorine and phosphorus.

8. A lubricant comprising about 95.5 per cent petroleum lubricating oil, about 2.5 per cent of diplienyl, and about 2 per cent of saponiflable oil containing an element in the group of sulphur. chlorine and phosphorus.

9. A lubricant comprising petroleum lubricating oil, 0.1 to 5 per cent diphenyl and sulphurized animal oil, said petroleum lubricating 011 being more than 80 per cent of the blend.

HARRY T. BENNETT. CLARE PRA'I'HER. 

